AIM To study the relationship between incisor retraction and soft tissue profile alterations and to identify and quantify the parameters that influence it. METHODS Pre- and posttreatment lateral cephalograms of 37 Class I and Class II Division 1 Iranian females in whom at least one maxillary premolar was bilaterally extracted were analyzed and compared. RESULTS Significant positive correlations were found between retraction of the maxillary and mandibular incisors and posterior movement of the upper lip (r=0.53, P<.001), the lower lip (r=0.63, P<.001), thickness increase of the upper (r=0.59, P<.001) and lower (r=0.69, P<.001) lip, increase of the soft tissue lower anterior face height (r=0.81, P<.001) and lower soft tissue component (r=0.49, P<.001), and an increase of the nasolabial angle (r=0.43, P<.01). The ratio of maxillary incisor to upper lip retraction was 2:1. CONCLUSION In Iranian girls, a strong correlation exists between anterior tooth retraction and the position and configuration of both lips.
AIM:To study in vitro the bond strength of three adhesive systems on lingual brackets.METHODS:Forty-five extracted human mandibular premolars were randomly divided into three groups of 15 specimens each. All brackets (Stealth lingual brackets) were bonded with Transbond XT Light Cure Adhesive. In group 1, the conventional primer was used; in group 2, Transbond Moisture Insensitive Primer was employed; and in group 3, an antimicrobial self-etching primer (Clearfil Protect Bond) was used.RESULTS:The highest mean bond strength values were observed when Clearfil Protect Bond (13.54 ± 0.58 MPa) was used and the lowest after applying the conventional Transbond XT primer (6.41 ± 0.43 MPa). The mean bond strength in group 2 was 8.20 ± 0.50 MPa, which was significantly higher than that of group 1.CONCLUSION:Besides its antimicrobial effect, Clearfil Protect Bond results in high bond strength values. Therefore, this product might be preferable when bonding lingual brackets.
AIM:To evaluate the frictional forces generated by ceramic- (Opal, Ultradent) and glass-fiber-reinforced polycarbonate self-ligating brackets (Oyster, Gestenco) and compare the effectiveness of these ligatureless systems with glass-fiber-reinforced polycarbonate conventional brackets (Blonde, Gestenco). The hypothesis is that there is no difference between frictional forces generated by ceramic- and glass-fiber-reinforced polycarbonate self-ligating and glass-fiber-reinforced polycarbonate conventional brackets. METHODS:Twelve preadjusted 0.022 3 0.028-inch maxillary canine brackets were tested, divided into three groups: Opal, Oyster, and Blonde. Frictional tests were conducted with the Emic DL 10000 testing machine with a 20 N loadcell for 40 seconds at a 0.5 cm/min speed. Each bracket-wire combination was tested five times. The data generated were analyzed by parametric analysis of variance (one-way ANOVA) and Bonferroni tests. RESULTS:Analysis of variance indicated significant differences for the three groups (P<.01). The frictional forces of the Oyster glass-fiber-reinforced polycarbonate self-ligating brackets were significantly lower (37.0 ± 8.9 cN) than those of the Opal ceramic-reinforced polycarbonate self-ligating brackets (49.5 ± 10.1 cN), while the Blonde glass-fiber-reinforced conventional bracket frictional forces were 105.8 ± 6.4 cN. CONCLUSION:Oyster glass-fiber-reinforced polycarbonate brackets produced less friction than Opal ceramic-reinforced polycarbonate brackets. The polycarbonate ligatureless system showed significantly lower frictional forces compared to Blonde conventional polycarbonate brackets tied with elastomeric ligatures. The study rejected the initial hypothesis because there are significant differences of frictional forces among the tested systems.
This study investigated the prevalence of signs and symptoms of temporomandibular disorders (TMD) in 1,134 orthodontically untreated children and adolescents (593 boys, 541 girls; age range 5 to 15 years) with and without crossbites. The sample with crossbites was further grouped according to the type (anterior, posterior, unilateral, or bilateral). The TMD symptoms bruxism (obvious active attrition/myalgia), joint sounds (clicking/crepitation), deviation during opening, reduced functional movements (maximum opening <40 mm), and myopain (originating in the masticatory muscles/related to masticatory functions) were evaluated based on the standardized RDC/TMD protocol (Research Diagnostic Criteria for Temporomandibular Disorders) and compared among the various groups. Girls had a significantly higher prevalence of myopain than boys (x(2)=3.882, P<.05). Furthermore, individuals with posterior unilateral crossbites showed a significantly higher prevalence of TMD symptoms (x(2)=33.877, P<.001) and reduced functional movements (x2 = 10.800, P<.05) than any other group. In conclusion, sex and type of crossbite play a role in the prevalence of TMD signs and symptoms.
AIMAccelerating the speed of orthodontic tooth movement should contribute to the shortening of the treatment period. This study was designed to determine whether a pulsed electromagnetic field (PEMF) affects orthodontic tooth movement.METHODSThe canines of one side of 10 patients (mean age 23.0 ± 3.3 years) who needed canine retraction were exposed to a PEMF; the canines on the contralateral sides of the same patients were not similarly exposed. After extraction of the maxillary first premolars, both canines were retracted with coil springs. A circuit and a watch battery were used to generate a PEMF (1 Hz). The generator was embedded in a removable appliance. Foil was used to obstruct the contol group from PEMF exposure. Patients were instructed to use the device from the commencement of canine retraction, and it was removed when Class I canine relationship was achieved in either of the canines after 5.0 ± 0.6 months. The changes in the space between the maxillary canine and first molar were measured to indicate the amount of tooth movement. The canine retraction distances were compared by paired t test. Afterward, the treatment plan was continued.RESULTSWith exposure to a PEMF, canine retraction was 1.57 ± 0.83 mm more than the control group (P<.001).CONCLUSIONThese findings suggest that application of a PEMF can accelerate orthodontic tooth movement.
Aim To determine the correlation among chronologic age, skeletal maturity, and dental age in reference to both sexes. Methods In 380 subjects (147 males and 233 females) between 7 and 17 years of age, skeletal maturity was assessed using the cervical vertebral maturation stages described by Baccetti et al. Dental age was determined using the Demirjian method. The correlation between skeletal maturity and chronologic age on one side and between skeletal maturity and dental age on the other was assessed with Spearman rank correlation coefficients. Pearson correlation coefficients were used to assess the correlation between chronologic and dental age. Results For both sexes, significant correlations among chronologic age, skeletal maturity, and dental age were found. The mandibular first premolar had the highest correlation with skeletal maturation in both sexes. Conclusion As skeletal maturity and dental age are significantly correlated, tooth development may be used to assess a patient's skeletal maturity at an early age.
AIM:To investigate the incidence of bacteremia in the bloodstream immediately after orthodontic mini-implant insertion, which can be an invasive procedure.METHODS:Blood samples (10 mL) were taken before and after mini-implant insertion from 40 patients (18 males, 22 females; mean age 21.3 ± 7.7 years). These samples were inoculated into BacT/Alert aerobic and anaerobic blood culture bottles and processed in a BacT/Alert 9240 Blood Culture System. The findings were analyzed with the McNemar test.RESULTS:No bacteremia was detected in the pretreatment samples, but it was in one of the postprocedure samples. The respective bacteria was Streptococcus sanguinis, which is strongly associated with bacterial endocarditis.CONCLUSION:Orthodontic mini-implant placement might possibly be correlated to transitory bacteremia. Therefore, a very careful approach seems indicated when dealing with patients who are at risk for cardiopathic complications.
This report presents a case of a patient who developed a supernumerary mandibular premolar during the course of orthodontic treatment. Evidence of this tooth comes from consecutive panoramic radiographs. It is not routine practice to screen for developing supernumerary teeth during orthodontic treatment. Therefore, the possibility of supernumerary tooth interference with occlusal development or orthodontic treatment should always be kept in mind. A brief review of literature concerning the late formation of supernumerary teeth is included.
AIM:To quantitatively assess the extent of morphologic changes of the apical root area and root length of maxillary central incisors after orthodontic treatment using digital subtraction radiography (DSR) and to investigate possible contributing parameters.METHODS:The subtracted images of panoramic radiographs of 21 patients before and after orthodontic treatment were evaluated using I/RAS C and Image J software. The retrieved data were analyzed by means of SPSS statistical software, and the method's error was assessed.RESULTS:There was a small but significant decrease of the root dimensions of the maxillary central incisors at the end of orthodontic treatment. The amount of root resorption was not significantly influenced by sex, age, dentition, malocclusion classification, extraction, overjet, overbite, elastic wear, and number of teeth with resorption as measured by DSR.CONCLUSION:DSR of pre- and posttreatment panoramic radiographs was able to confirm minor root resorption of the maxillary central incisors after orthodontic treatment.
When patients of differing ethnicities are treated with one bracket system, negative consequences for the occlusion can result. This study investigated the crown angulation and inclination on study casts of 60 Northern Thais (30 males and 30 females) with a good occlusion. In all study casts, each tooth (except the third molars) was evaluated with the orthodontic Torque Angulation Device (TAD) twice on the right side; this was also performed twice on the left side. The mean of the two evaluations was used for the statistical analysis. The means of the males and females were compared with the independent Student t test. The results were that the crown angulation of the mandibular first and second molars was significantly higher in females (P<.01) and that the crown inclination of all teeth did not differ between the two sexes.
AIM:To determine the parameters for an ideal smile.METHODS:Ten laypersons classified frontal photographs of 62 smiling individuals between 18 and 25 years of age into five categories: 1, poor; 2, fair; 3, good; 4, very good; and 5, excellent. The scores obtained for each smile were averaged. The five smiles with each the highest and lowest scores were analyzed for seven parameters: buccal corridor, smile index, smile symmetry, smile line ratio, upper lip line, smile arc, and upper lip curvature.RESULTS:The five smiles with the highest scores were symmetrical with an average upper lip line and a consonant smile arc. Three of the five had an upward upper lip curvature. The smile line ratio, buccal corridor, and smile index for all five subjects ranged from 1.0 to 1.3 mm, 9.0% to 11.0%, and 4.0 to 6.0 mm, respectively. Two of the five smiles with the lowest scores were asymmetrical and three had a high upper lip line and a downward curvature, but all five had a nonconsonant smile arc. The smile line ratio, buccal corridor, and smile index for all five subjects ranged from -1.0 to 1.3 mm, 18.0% to 22.0%, and 7.0 to 10.0 mm, respectively.CONCLUSION:The seven investigated smile parameters can define characteristics of an ideal smile. These smile components should be included in the orthodontic problem list to help clinicians select the appropriate mechanotherapy.
AIM:To evaluate the effect of a myofunctional appliance--the preorthodontic trainer (POT)--on the perioral and masticatory muscles by electromyography (EMG) in individuals with an Angle Class II, Division 1 malocclusion.METHODS:Twenty children were treated with a POT appliance, which had to be worn every day for 1 hour and overnight. The EMG recordings were made at the beginning and end of POT therapy during maximal clenching, swallowing, and sucking. For statistical evaluation, the Wilcoxon nonparametric test was used at the P<.05 level.RESULTS:During POT treatment, the EMG value for clenching of the anterior temporal muscle decreased significantly (P<.001). Also, for the mentalis muscle, the EMG value during clenching decreased significantly; for the orbicularis oris muscle, this was true for sucking (P<.05) and clenching (P<.01). For the masseter muscle, all EMG values were decreased during treatment but significantly only for clenching.CONCLUSION:During the 6 months of POT treatment, the perioral and masticatory muscles of Class II, Division 1 patients improved significantly.
AIM:Rapid palatal expansion (RPE) is used for treatment of skeletal crossbites. It may be combined with a face mask if the maxilla is to be protracted. Conventional tooth-borne appliances rely on an almost complete dentition to transmit the relatively high forces to the bony structures of the maxilla and midface. In most situations, tooth-borne appliances produce adverse effects such as buccal tipping of the lateral teeth, imposing the risk of recessions and vestibular bone fenestrations. To overcome these drawbacks, an RPE appliance was developed that utilizes mini-implants anteriorly in the palate for skeletal anchorage. Because this device is also attached to the first molars, it can be denominated as a bone- and tooth-borne appliance (hybrid hyrax). The objective of this clinical pilot study was to investigate its dental and skeletal effects.METHODS:RPE was performed in 13 patients (seven females, six males; mean age 11.2 years). In 10 patients with a skeletal Class III occlusion, a face mask was used simultaneously for maxillary protraction. Three-dimensional scans of the individual study models were digitally superimposed for the assessment of the dental effects. Skeletal effects were evaluated by lateral cephalograms taken before and after RPE and protraction.RESULTS:The time needed to achieve the intended expansion ranged from 4 to 14 days (mean 8.7 ± 3.6 days). The mean expansion in the first premolar/first primary molar region was 6.3 ± 2.9 mm and 5.0 ± 1.5 mm in the first molar region. The Wits appraisal changed from -5.2 ± 1.3 mm to -2.5 ± 1.5 mm (mean improvement 2.7 ± 1.3 mm). The right first molar migrated 0.4 ± 0.6 mm mesially and the left one 0.3 ± 0.2 mm.CONCLUSIONS:The hybrid hyrax is effective for RPE and can be employed especially in patients with reduced anterior dental anchorage. Since most teeth are not in the appliance, regular orthodontic treatment can start early. The combination of the hybrid hyrax with a face mask for maxillary protraction appears to be effective in minimizing mesial migration of the dentition.
Esthetic orthodontic appliances continue to appeal to more patients, which results in objections to extraction spaces that remain for several months during orthodontic therapy. This has led orthodontists to design temporary pontics that fill extraction sites and that can be reduced as the spaces close. This report describes a simple, efficient, and expeditious technique for making such pontics.
Caring for patients with bilateral cleft lips and palates requires an interdisciplinary approach. The treatment of such a patient is described. Therapy comprised maxillary expansion, mini-implant insertion, premaxillary osteotomy, and vomeroplasty, which led to a drastic improvement of the occlusion and facial appearance.
The present article illustrates a treatment option for managing the skeletal Class II malocclusion complicated by a deep bite and short face in an adult and emphasizes the limitations of such an approach and its potential complications. The patient had an inadequate tooth display upon smiling and a deep lower curve of Spee. Treatment consisted of a double jaw surgery with a maxillary three-piece LeFort to expand, downgraft, and advance the maxilla and a bilateral sagittal split osteotomy to advance the mandible. Treatment was staged so that the leveling of the mandibular arch was completed postsurgically by extrusion of the mandibular buccal segments. During surgery, the mandible was rotated clockwise at the osteotomy site to bring the chin down. This treatment approach resulted in a dramatic increase in the lower facial height, as well as an improvement in skeletal and occlusal relationships, with a much improved tooth display upon smiling, despite the few complications that occurred.
AIMS:To assess the rate of tooth movement, anchorage loss, root resorption, and alkaline phosphatase (ALP) activity in the gingival crevicular fluid (GCF) as a marker for bone remodeling during orthodontic space closure using two different mechanisms.METHODS:Space closure was completed in 20 patients with extraction of all 4 premolars. Lateral cephalograms and radio-visiographs taken before (T1) and after (T2) space closure were assessed for anchorage loss and root resorption. Alkaline phosphatase levels were measured in 10 patients, which were divided into two groups of five each. Spaces were closed with a screw device in the first group and with active tie-backs in the second. Gingival crevicular fluid samples, collected at intervals, were assayed for alkaline phosphatase spectrophotometrically in each patient.RESULTS:The mean rate of tooth movement was 1.32 ± 0.22 mm/month. The mean amount of anchorage loss in the maxilla and mandible was 1.23 ± 0.60 mm and 1.08 ± 0.65 mm, respectively. Sixty (25%) roots showed no root resorption, while 180 (75%) roots displayed mild to moderate blunting of their apices. Gingival crevicular fluid-alkaline phosphatase level increased significantly from day 7 to day 28 in both groups, but significantly more in the screw retraction group (P<.05).CONCLUSION:It is possible to infer that space closure occurs more rapidly with sequential repetitive loading of the periodontal ligament than with conventional active tie-backs. This observation is in concurrence with a significant increase in the gingival crevicular fluid-alkaline phosphatase level.
AIM:To determine the malocclusion complexity and orthodontic treatment need in urban Iranian schoolchildren using the Index of Complexity, Outcome, and Need (ICON) and the Index of Orthodontic Treatment Need (IOTN) and to also assess the relationship between these indices.METHODS:The study sample comprised 502 individuals (253 girls and 249 boys, 11 to 14 years of age), of whom one girl and five boys already had an orthodontic appliance at the time of the survey. In those individuals not wearing orthodontic appliances (n=496), the definitive treatment need (ICON>43) and compartments of the ICON were defined and compared between sexes. The Aesthetic Component and Dental Health Component (DHC) of the IOTN were also recorded. Scatter plots and Spearman rank correlation coefficients were used to explore the relationships between the ICON and DHC and the Aesthetic Component (AC) of the IOTN.RESULTS:According to ICON, DHC (IOTN), and Aesthetic Component (IOTN), 46.6%, 36.1%, and 17.9%, respectively, of the studied children needed orthodontic treatment; however, only 1.1% wore an appliance. In terms of complexity, 26.4% of the studied individuals were considered to have a difficult or very difficult malocclusion. With regard to treatment needs, significant correlations existed between the ICON scores and DHC (IOTN) (r=0.93) and between the ICON scores and the esthetic component (IOTN) (r=0.96). The threshold for treatment need was lower in the ICON than in the IOTN. Of the children who were classified in the borderline category of the IOTN (DHC=3), 52.0% were in need of treatment according to their ICON score (ICON>43). No sex difference was found for treatment need (ICON>43, P>.05) and treatment complexity (P>.05).CONCLUSION:According to the ICON, 46.6% of the Iranian schoolchildren need orthodontic treatment. ICON is a good substitute for the IOTN, yet it results in a lower treatment-need threshold.
To determine with a cross-sectional study the prevalence of orthodontic treatment need using the Dental Aesthetic Index (DAI).Using a stratified sampling method in private and public schools in Isfahan, Iran, 748 subjects were examined and divided into three age groups: 11 to 14, 14 to 17, and 17 to 20 years (355 females and 393 males, 15.11 ± 2.23 years), including 20 subjects with history of orthodontic treatment. DAI scores were recorded in those without history of orthodontic treatment (n=728, 340 females and 388 males). The proportions of subjects within sexes needing treatment, as defined by having DAI scores of at least 31, were compared using the chi-square test. The chi-square test was also used to test for any difference for DAI treatment categories in different age groups and also to test for sex dimorphism.The mean DAI score was 26.14 (SD=7.64) points (95% CI, 26.60 to 26.72). On the whole, 54.5% showed no need or slight need for treatment. In 23.6%, the need for treatment was elective. However, in 11.0%, treatment was highly desirable and 10.9% showed very severe malocclusions and treatment was mandatory. There was a significant difference between sexes with regard to DAI treatment need categories (chi-square=10.10, df=3, P<.05). There was no significant difference between different age groups with regard to DAI treatment categories (P>.05).According to our findings, 21.8% of the evaluated Iranian school children in our sample had a DAI score above or equal to 31 points, suggesting highly desirable or mandatory orthodontic treatment need.
AIM:To examine the level of discomfort and pain reported by patients during debonding of orthodontic metallic brackets by comparing two of the most popular methods, since discomfort can negatively influence patients' motivation to undergo orthodontic treatment.METHODS:This split-mouth designed study involved 37 patients. Two methods were used for bracket removal: a lift-off debonding instrument and a ligature-cutting plier. The level of discomfort during debonding was evaluated on a scale of 0 to 4; The Adhesive Remnant Index (ARI) was taken into consideration, as well. Comparison between the methods was statistically analyzed by using the Wilcoxon signed rank and chi-squared tests (P<.05).RESULTS:Regarding the remnant adhesive, no significant difference was observed between the methods. Patients' reports of pain (score ≥2) were observed in 24.3% of teeth when the brackets were removed using a ligature-cutting plier, while there was a 12.8% report of pain when the lift-off instrument was employed (odds ratio [OR]=2.17, P<.001, χ(2)=17.7). Statistically significant lower scores for maxillary (P=.02) and mandibular central incisors (P=.02), maxillary lateral incisors (P=.02), mandibular canines (P=.00), and mandibular premolars (P=.00/.02) were reported when the lift-off instrument was employed.CONCLUSION:For the removal of orthodontic brackets, the lift-off instrument is better accepted by patients compared to the ligature cutting pliers, given that reports of pain are about two times lower with the former. The ARI was the same for both methods.
